In a previously designed system and process described in U.S. Pat. No. 4,780,269 (as seen in FIGS. 1-4), a spent fuel storage system 10 uses a dry shielded canister 12. The canister assembly 12 is inserted into a transfer cask 14. The transfer cask 14 and canister assembly 12 can be placed by a crane 16 into an irradiated fuel storage pool 18 filled with water (see FIG. 1). Irradiated fuel contained in fuel assemblies (see, e.g., fuel assembly 20) can be stored in the pool 18.
To remove the irradiated fuel from the pool 18, the fuel is placed in the canister assembly 12, and appropriate seals and covers (as described below) are affixed to the canister assembly 12 before the transfer cask 14 is removed from the pool 18. Referring to FIG. 2, upon removal from the pool 18, water can be forced out of both the canister assembly 12 and the transfer cask 14 with a pressurized gas being applied through selected ports of the canister assembly and cask. The canister assembly 12 can further be dried by using a vacuum pump to evacuate the residual water from the canister assembly 12. After evacuation of the canister assembly 12, helium or another gas may be pumped into the canister assembly 12. As the transfer cask 14 (containing the canister assembly 12 and irradiation fuel assemblies 20) is removed from the pool 18, appropriate radiation shielding is provided for the contained irradiated fuel assemblies by the shielded end plugs of the canister assembly 12 and the transfer cask 14.
Referring now to FIG. 3, the transfer cask 14 can be loaded into a horizontal position onto a transfer trailer 22 having a specially designed skid 24. The skid 24 allows the transfer cask 14 to be moved in three dimensions to permit alignment of the cask 14 with a horizontal storage module (HSM) 26, which can be seen in FIG. 4, for dry storage of the canister assembly 12.
Referring to FIG. 4, the cask 14 is aligned with a port 28 in the HSM 26 to extract the canister assembly 12 from the transfer cask 14 for storage in the horizontal storage module 26. In the illustrated embodiment, a hydraulic ram 30 is at least partially insertable through a second port 32 at the opposite end of the dry storage module 26 to extract the canister assembly 12 from the transfer cask 14 for storage in the horizontal storage module 26. Alternatively, a winch (not shown) or another extraction device could be used in place of ram 30 to extract the canister assembly 12 from the transfer cask 14. It should further be appreciated that the reverse operation of pushing the canister assembly 12 into the dry storage module 26 can also be accomplished.
There exists a need for improvements to the previously designed storage system and method. Embodiments of the present disclosure aim to improve these and other systems and methods.